Cellular radio systems may involve a layered protocol where one layer needs to include large SDUs (service data units), which arrive as inputs from a different layer, within its own output PDUs (protocol data units). One example of this is within HSDPA (high speed uplink packet access) in UMTS (universal mobile telecommunications system) where multiple MAC (medium access control) SDUs are included within a MAC PDU.
When including SDUs that are very large or that are larger than the current PDU size, it is necessary to segment these SDUs to allow them to fit across multiple PDUs, and avoid excessive padding. The existing method within 3GPP for indicating the inclusion of multiple SDUs is not very flexible when considering, for instance, the information required within the PDU to indicate the size of each of the SDUs. 3GPP (third generation partnership project) TS (technical standard) 25.321, v. 6.9.0 (2006 June) sections 9.1.4 and 9.2.2 illustrate current techniques for inclusion of SDUs within the MAC PDU.
Thus those skilled in the art seek apparatus, methods and computer program products that overcome the limitations of the prior art.